August 6, 2014: Dr. Margarita Karovska (Harvard-Smithsonian Center for Astrophysics) and colleagues have requested AAVSO observer assistance in their campaign on the symbiotic variable RT Cru. Weekly or more frequent monitoring beginning now is requested in support of upcoming Chandra observations still to be scheduled.

Dr. Karovska writes: "RT Cru is a fascinating member of a new class of hard X-ray emitting symbiotic binaries. The RT Cru system contains a high-mass white dwarf accreting from a mass-losing M giant. The white dwarf is surrounded by an accretion disk fed by the wind of the red giant.

"We plan Chandra observations of RT Cru in the near future that will help us understand the characteristics of the accretion onto the white dwarf in this sub-class of symbiotics. This is an important step for determining the precursor conditions for formation of a fraction of asymmetric Planetary Nebulae, and the potential of symbiotic systems as progenitors of at least a fraction of Type Ia supernovae.

"RT Cru is an optically variable source and has been observed sporadically, with a higher concentration of observations during a recent outburst from a couple of years ago. We are requesting regular optical monitoring (B and V photometry) of this source (on a weekly basis if possible)." Visual observations are also encouraged.